PTH (Intact Parathyroid Hormone)
Understanding PTH (Intact Parathyroid Hormone)
What is PTH (Intact Parathyroid Hormone)?
A PTH (Intact Parathyroid Hormone) test assesses the level of parathyroid hormone (PTH) that plays a crucial role in regulating calcium and phosphorus levels in the body. This test helps evaluate parathyroid gland function and primarily diagnose conditions related to calcium imbalance.
Parathyroid hormone (PTH) is produced by the parathyroid glands, four small glands located near the thyroid gland in the neck. PTH plays an important role in regulating the levels of calcium and phosphorus in the body. It helps maintain calcium balance by influencing its absorption from the intestines, release from bones, and reabsorption by the kidneys. PTH ensures that the concentration of calcium in the blood stays within a normal range as it is essential for various physiological functions, including bone health, nerve transmission, and muscle contraction.
A PTH (Intact Parathyroid Hormone) test helps in assessing the function of the parathyroid gland and identifying conditions associated with imbalances in calcium and, to some extent, phosphorus. Understanding PTH levels can provide valuable insights into bone health, kidney function, and disorders related to mineral metabolism. Regular monitoring of PTH levels is essential for individuals with conditions affecting calcium homeostasis and those at risk of bone disorders or kidney problems. Additionally, this test can be done when individuals exhibit symptoms related to calcium and phosphorus imbalance, such as persistent bone pain, impaired kidney function, long-term digestive problems, pain or discomfort in joints, muscle weakness, etc. Also, it can be done when your routine blood tests show abnormal calcium or phosphorus levels. These symptoms may indicate disorders such as hypoparathyroidism or hyperparathyroidism, where parathyroid glands are either underactive or overactive, respectively.
Overnight fasting for at least 8-12 hours is needed before undertaking a PTH (Intact Parathyroid Hormone) test. However, drinking water before the test is acceptable. PTH is released in a rhythmic pattern, with increased levels during the night; therefore, you may need to take the test at a certain time of day. Also, tell your doctor about all the medications or supplements, including calcium, that you are taking before undertaking this test, as these may interfere with the test results.
Lab test results may vary across different laboratories. Abnormal test results require an expert interpretation; therefore, never try to self-medicate at home based solely on these results, and always consult a doctor for a proper understanding of the test results. The insights from a PTH (Intact Parathyroid Hormone) test help the doctor tailor a treatment plan to address specific problems like hypoparathyroidism or hyperparathyroidism and target to restore calcium balance in the body.
What is PTH (Intact Parathyroid Hormone) used for?
A PTH (Intact Parathyroid Hormone) test is done:
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To evaluate parathyroid gland function.
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To diagnose conditions associated with calcium imbalance.
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To diagnose and monitor disorders like hypoparathyroidism or hyperparathyroidism.
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To monitor patients with chronic kidney disease.
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To assess bone health and risk of osteoporosis.
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To determine the effectiveness of ongoing treatment for parathyroid disorders.
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To monitor surgical treatment for hyperparathyroidism.
What does PTH (Intact Parathyroid Hormone) measure?
A PTH (Intact Parathyroid Hormone) test measures the levels of parathyroid hormone (PTH) in the blood. PTH regulates calcium and phosphorus levels in the body. PTH levels are regulated by a feedback loop with calcium in the blood. Low calcium stimulates PTH release, and high calcium inhibits it. Problems like tumors or damage to the parathyroid glands can disrupt this balance, leading to abnormal PTH levels.
Monitoring of PTH levels is important in managing disorders affecting bone and mineral metabolism, and a PTH (Intact Parathyroid Hormone) test helps assess the function of parathyroid glands and diagnose conditions related to calcium and phosphorus imbalance.
Interpreting PTH (Intact Parathyroid Hormone) results
Interpretations
Reference ranges may vary in different labs.
An Intact Parathyroid Hormone Test is performed together with a Blood Calcium Test to determine the cause of calcium deficiency, and the results are interpreted as follows:
Calcium |
PTH |
Interpretation |
Normal |
Normal |
Blood calcium regulation normal |
Low |
High |
Parathyroid gland normal, low Calcium levels are due to other causes |
Low |
Normal/Low |
PTH secretion low, hypoparathyroidism may be indicated |
High |
High |
Hyperparathyroidism may be indicated |
High |
Low |
Parathyroid gland normal, high Calcium levels are due to other causes |
Normal |
High |
Mild hyperparathyroidism |